Which investor became Facebook’s first outside angel investor in 2004?

Peter Thiel became Facebook’s first outside angel investor in 2004.

Thiel, a technology entrepreneur and co-founder of PayPal, invested $500,000 in Facebook in September 2004. The investment gave the young company important early funding while it was still expanding from Harvard to other universities. Thiel also joined Facebook’s board and remained an influential early backer.

The investment is often confused with later venture-capital financing. Accel invested $12.7 million in Facebook in 2005, a much larger round that helped the company expand nationally. Thiel’s investment came first and is generally described as Facebook’s initial outside funding.

Thiel’s role was financial and strategic rather than operational. He was not Facebook’s first president or chief operating officer. Those roles belonged to other people during the company’s early development, while Thiel’s best-known connection to Facebook is his early investment and board membership.